当vlan为802.1q vlan且处于缺省状态时，在vlan 1视图下执行带有user-group的添加端口的操作，系统就会自动进入port-based vlan状态并给出提示。

    当vlan为port-based vlan且处于缺省状态时，执行新增vlan或者改变端口为trunk类型的操作，系统就会自动进入802.1q vlan状态并给出提示。

    1、802.1q vlan的缺省状态为只存在vlan 1，且所有端口为access端口。

    2、port-based vlan的缺省状态为只有一个vlan 1存在，且所有端口只属于user-group 1。

    例：切换vlan。

    # vlan为802.1q vlan且处于缺省状态时，将其切换为port-based vlan，创建user-group 2且添加端口2到user-group 2中。

    [h3c] system-view

    enter system view, return to user view with ctrl+z.

    [h3c] vlan 1

    [h3c-vlan1] port gigabitethernet 0/2 user-group 2

    the vlan state has been changed to port-based vlan!

    # vlan为port-based vlan且处于缺省状态时，将其切换到802.1q vlan状态且创建vlan 2。

    [h3c] system-view

    enter system view, return to user view with ctrl+z.

    [h3c] vlan 1

    [h3c-vlan1]vlan 2

    the vlan state has been changed to 802.1q vlan!